This application is based on patent application Ser. No. 2000-20903 filed Jan. 28, 2000 in Japan, the content of which is incorporated hereinto by reference.
1. Field of the Invention
The present invention relates to a printing-medium type discrimination device and a printing apparatus that uses the device.
2. Description of the Related Art
In connection with a trend of printing apparatuses toward higher resolution in recent years, there has been adopted a method for rendering a variety of colors, for example, by depositing a plurality of printing agents each having a different color on the substantially same position of a printing medium. However, because of a relationship between a characteristic of the printing agent and the type of printing medium, there may be cases where a difference occurs between qualities of images formed on different printing media in performing the printing even under the same printing condition. For example, in ink jet printing apparatuses that use inks as the printing agents, a state how the ink penetrates into the printing medium differs depending on the type of printing medium because of the inherent characteristic of the ink; therefore even when the printing is executed by the same printing method and with the same ejection quantity, a large difference may occur in terms of the quality of images formed on the printing media.
Moreover, an ink jet printing apparatus that ejects a specific solvent for preventing bleeding of an ink on the printing medium cannot achieve an intended effect on printing mediums that have a coating layer on one face, and consequently printing on such printing media causes useless consumption of the inks, the solvent, and the printing media.
Therefore, it is highly desirable that various printing conditions, such as the type of ink to be used in the printing, the ejection quantity, the type of printing medium, etc. should be selected and set up properly in consideration of their mutual relationships.
However, since such selection is entrusted to each user in conventional printing, the user is forced to make a proper judgment. Further, with increasing types of printing medium, the user""s judgment or selection for the printing may become more complicated.
With this view, there has been investigated a printing apparatus that can discriminate the type of printing medium loaded therein and select optimal printing conditions. More specifically, there is a printing apparatus that uses means for measuring the optical reflectance of the face of the printing medium with a reflection-type optical sensor as one method of acquiring information of the printing medium. Here, the reflection-type optical sensor is a sensor that can irradiate an object with light and can measure the amount of reflected light. That sensor can perform necessary discrimination through a process where the optical reflectance of the face on which the printing should be performed originally of the printing medium is measured beforehand for a plurality of printing media and the reflectance of the printing medium to be used for the printing is compared with those measured values
However, since there exist printing media of different types that have substantially same reflectances, it is difficult for this method to discriminate all the types of the printing media correctly.
It is the object of the present invention to discriminate the type of printing medium with a high degree of accuracy and thereby various printing conditions can be selected and set up properly.
In a first aspect of the present invention, there is provided a printing-medium type discrimination device applied to a printing apparatus for performing printing on a printing medium, comprising:
means for acquiring information of both a front side face on which the printing will be executed and a back side face of the printing medium (i.e., two pieces of information); and
means for discriminating the type of the printing medium through the use of the acquired two pieces of information.
The discriminating means may conduct discrimination through the use of reference values for the two pieces of information.
The discriminating means may conduct the discrimination through the use of reference values for the two pieces of information and a difference value between the two pieces of information.
The information acquisition means may have means for irradiating each of the faces of the printing medium with light and measuring the quantity of reflected light obtained therefrom.
The information acquisition means may have an image pickup device for reading respective patterns of the faces of the printing medium.
The information acquisition means may have means for measuring respective friction forces of the faces of the printing medium.
The information acquisition means may have means for reading inherent information that has been formed on one of the faces of the printing medium beforehand.
In a second aspect of the present invention, there is provided a printing medium that bears information concerning its own type on itself, wherein the information is provided at a position that can be read by means for acquiring information of both the front side face on which printing will be executed and the back side face of the printing medium.
In a third aspect of the present invention, there is provided a printing apparatus for performing printing on a printing medium by using a print head, comprising:
means for acquiring information of both a front side face on which the printing will be executed and a back side face of the printing medium;
means for discriminating the type of the printing medium through the use of the acquired two pieces of information; and
means for executing the printing that is suited to the printing medium on which the printing is to be executed according to the discrimination of the discriminating means.
The printing execution means may have means for changing a specified print mode according to the discriminated printing medium type.
The printing apparatus according to the third aspect of the present invention may further comprise means for judging whether or not the printing medium is loaded In the state of the face on which the printing should be originally performed being reversed through the use of the two pieces of information when the printing-medium type discrimination means failed to conduct the discrimination.
The printing apparatus according to the third aspect of the present invention may further comprise means for giving the user predetermined information and halting the printing when the discriminating means judges the printing medium to be loaded in the state of the face on which the printing should be originally performed being reversed and means for continuing or halting the printing according to the user""s instruction indicating whether the printing is to be continued or not, when the judgment regarding the state of the face on which the printing should be originally performed being reversed is not made.
In a fourth aspect of the present invention, there is provided a printing system, comprising:
a printing apparatus having means for acquiring information of both a front side face on which the printing will be executed and a back side face of a printing medium, means for discriminating the type of the printing medium through the use of the acquired two pieces of information, and means for executing the printing that is suited to the printing medium on which the printing is to be executed according to the discrimination of the discriminating means; and
an image data supplying apparatus for supplying an image data to be printed to the printing apparatus.
In a fifth aspect of the present invention, there is provided a printing-medium type discrimination method applied to a printing apparatus for performing printing on a printing medium, comprising the steps of:
acquiring information of both a front side face on which the printing will be executed and a back side face of the printing medium; and
discriminating the type of the printing medium through the use of the acquired two pieces of information.
In a sixth aspect of the present invention, there is provided a printing method for performing printing on a printing medium by using a print head, comprising the steps of:
acquiring information of both a front side face on which the printing will be executed and a back side face of the printing medium;
discriminating the type of the printing medium through the use of the acquired two pieces of information; and
executing the printing that is suited to the printing medium on which the printing is to be executed according to the discrimination.
In a seventh aspect of the present invention, there is provided a printing method applied to a printing system comprising an image data supplying apparatus and a printing apparatus, the method comprising the steps of:
supplying an image data to be printed to the printing apparatus from the image data supplying apparatus;
acquiring information of both a front side face on which the printing will be executed and a back side face of a printing medium before printing of the image data;
discriminating the type of the printing medium through the use of the acquired two pieces of information; and
executing the printing that is suited to the printing medium on which the printing is to be executed according to the discrimination.
In an eighth aspect of the present invention, there is provided a program for performing a printing-medium type discrimination method applied to a printing apparatus, the method comprising the steps of:
acquiring information of both a front side face on which the printing will be executed and a back side face of a printing medium; and
discriminating the type of the printing medium through the use of the acquired two pieces of information.
In a ninth aspect of the present invention, there is provided a program for performing a printing method for executing a printing on a printing medium by using a print head, the method comprising the steps of;
acquiring information of both a front side face on which the printing will be executed and a back side face of the printing medium;
discriminating the type of the printing medium through the use of the acquired two pieces of information; and
executing the printing that is suited to the printing medium on which the printing is to be executed according to the discrimination.
In a tenth aspect of the present invention, there is provided a program for performing a printing method applied to a printing system comprising an image data supplying apparatus and a printing apparatus, the method comprising the steps of:
supplying an image data to be printed to the printing apparatus from the image data supplying apparatus;
acquiring information of both a front side face on which the printing will be executed and a back side face of a printing medium before printing of the image data;
discriminating the type of the printing medium through the use of the acquired two pieces of information: and
executing the printing that is suited to the printing medium on which the printing is to be executed according to the discrimination.
In any one of the above aspects of the present invention, an ink jet print head for ejecting an ink as a print agent to the printing medium may be used.
The ink jet print head may have an electrothermal transducer to generate a thermal energy for causing film boiling in the ink as an energy used to eject the ink.
The present invention as described above makes it possible for the printing apparatus: to discriminate the printing medium automatically with a high degree of accuracy; to perform the printing in a proper print mode; and to form an image with such image quality as is best suited to the printing medium, while eliminating the need for the user to change the setting intentionally, through furnishing of a function of automatically discriminating the type of printing medium, for example, by measuring the optical reflectances of a front side face and of a back side face of the printing medium, calculating the difference value of these reflectances, and comparing them with previously-measured reference values.
Incidentally, in this specification, a word xe2x80x9cprintxe2x80x9d (or xe2x80x9crecordxe2x80x9d) refers to not only forming significant information, such as characters and figures, but also forming images, designs or patterns on printing medium and processing media, whether the information is significant or insignificant or whether it is visible so as to be perceived by humans.
The word xe2x80x9cprinting mediumxe2x80x9d include not only paper used in common printing apparatus, but cloth, plastic films, metal plates, glass, ceramics, wood, leather or any other material that can receive ink.
Further, the word xe2x80x9cinkxe2x80x9d should be interpreted in its wide sense as with the word xe2x80x9cprintxe2x80x9d and refers to liquid that is applied to the printing medium to form images, designs or patterns, process the printing medium or process ink.